Bhagavata Purana 5.26.11
Srimad Bhagavatam · 26 · Verse 11
Sanskrit Original
ये त्विह यथैवामुना विहिंसिता जन्तव: परत्र यमयातनामुपगतं त एव रुरवो भूत्वा तथा तमेव विहिंसन्ति तस्माद्रौरवमित्याहू रुरुरिति सर्पादतिक्रूरसत्त्वस्यापदेश: ॥ ११ ॥
ye tv iha yathaivāmunā vihiṁsitā jantavaḥ paratra yama-yātanām upagataṁ ta eva ruravo bhūtvā tathā tam eva vihiṁsanti tasmād rauravam ity āhū rurur iti sarpād ati-krūra-sattvasyāpadeśaḥ.
In this life, an envious person commits violent acts against many living entities. Therefore after his death, when he is taken to hell by Yamarāja, those living entities who were hurt by him appear as animals called rurus to inflict very severe pain upon him. Learned scholars call this hell Raurava. Not generally seen in this world, the ruru is more envious than a snake.